Left 4 Dead

Left 4 Dead
Developer(s)	Turtle Rock Studios
Publisher(s)	Valve Template:Infobox/engine
Release date	Steam: November 18, 2008 Retail & Xbox 360: November 18, 2008 (NA) November 21, 2008 (EU)
Genre	Survival horror
Mode(s)	1-8 players (4 survivors + 4 infected)
Age rating(s)	ESRB: RP
Platform(s)	Windows, Xbox 360
Credits | Soundtrack | Codes | Walkthrough

Left 4 Dead is a co-operative, survival horror, first-person shooter game by Valve Corporation. The game uses the Source game engine, and is available for Windows-based personal computers and the Xbox 360.

Left 4 Dead puts four human playable or AI controlled survivors of an apocalyptic pandemic against hordes of aggressive "Infected" zombies in a cinematic backdrop in which the players "star" as each character in a fictional movie. The Survivors' goal is to help each other make it through various scenarios to safety. The Infected are controlled by an AI that dynamically balances difficulty and mood depending on the players' progress and situation. In an alternate game mode, human players can control up to four different monsters with special abilities and cooperate to stop the Survivor players.

It was released on November 18, 2008 in the United States and November 21, 2008 in Europe to coincide with the tenth anniversary of the release of Half-Life. A five-minute trailer was released on Halloween. A playable demo was made available on November 6 for pre-purchasers and on November 11 for the general public. The playable demo was closed on November 18, 2008. The demo contained the first one and a half out of five maps of the "No Mercy" campaign and was playable in both single player and multi-player. Left 4 Dead went gold on November 13, 2008.

Gameplay

Played in first person, players take control of the four main characters of the game, known as the Survivors. If four human players are not available to play, the remaining Survivors can be AI-controlled bots. They play through the levels fighting off the Infected, which are living humans (not traditional undead zombies, although they are referred to as such by the characters), who have been infected with a mutated rabies virus.

The game is focused on cooperation and team play; coloured outlines of teammates are visible through walls to help players stick together and coordinate their movement, and Survivors can be knocked down by the Infected and only helped up by another player. If a teammate is knocked down after being helped up twice, without tending to his wounds in between, the player will experience distorted black-and-white vision, and the next takeout will kill the player, forcing them to wait until the survivors find a safe room before respawning. There are respawn areas scattered around the map that can be opened to find respawned survivors.

"Boss Infected" also command special attacks, such as a Hunter's pounce, Boomer's vomit, the Smoker's tongue-choke, and the Tank's throw (usually throws cars), which require assistance from a teammate to get out of or to get back up after being knocked down. Survivors can also share first-aid kits and help each other heal. Left 4 Dead has full friendly fire during the Advanced and Expert modes, increasing the need for caution around other Survivors. It is disabled in Easy mode.

The Survivors communicate by voice commands that are accessed by quick menus, and some will also sound off automatically when doing such things as reloading or spotting Infected. Over 1000 unique lines have been recorded for each Survivor. Additional communication of player actions is conveyed through character lights. Also, weapon-mounted flashlights and muzzle flashes help the players in determining whether their companions are shooting, performing melee attacks, reloading or moving. Due to control issues and to the fact that players will probably be using a LIVE headset, the Xbox 360 version of Left 4 Dead will omit the quick phrases feature.

The game is experienced through four scenarios that take place in various urban and rural locales, such as a hospital, an airport and a murky countryside. Each scenario is divided into several shorter sections marked by safehouse checkpoints, where players can heal, re-arm, calm their nerves, and revive players who were killed. Specifically, the four phases of the campaign mode are: No Mercy (urban setting), Death Toll (small town/countryside setting), Dead Air (airport setting), and Blood Harvest (woodland/nature setting). The levels are essentially linear, with distinct beginnings and ends, but there are a number of alternate routes to follow with more supplies and alternate objectives, as well as create a sense of non-linearity. At the end of each scenario, the players must defend a position from an onslaught of Infected until rescue arrives. Each scenario lasts between 45 and 75 minutes.

AI and the Director

The artificial intelligence of Left 4 Dead features a dynamic system for game dramatics, pacing, and difficulty called the Director. Instead of set spawn points for enemies, the Director places enemies and pick-ups (e.g. weapons, bombs, etc.) in varying positions and numbers based upon each player's current situation, status, skill and location, creating a new experience for each playthrough. The Director also creates mood and tension with emotional cues such as visual effects, dynamic music, and character communication.

Versus mode

Left 4 Dead will introduce a new 8-player versus experience. In the deathmatch Versus mode, four additional players can take control of powerful Infected with unique abilities, amongst the other AI-controlled Infected. The Infected players are randomly assigned which boss Infected to play as, which changes with each spawn. The Tank only spawns once per level, excluding the finales. Infected players will receive a message which informs the players who will become the Tank. The Witch is the only Boss-Infected that cannot be controlled by players. While playing as a Boss-Infected, the player will also have a limited "squad" leadership among the normal Infected. The Infected have the ability to see Survivors through the walls at a certain range if the Survivors are running, have the flashlight on, or are talking. The Infected can also see in the dark, unlike the Survivors. Infected spawn ahead of the Survivors and can, if they stay still, see a marker for their likely path of advance so they can set up ambushes. Throughout levels, Infected-only ways up buildings are marked with symbols. These can be climbed and used for ambushes, especially with the Infected immunity to falling damage. Versus mode is only playable on No Mercy and Blood Harvest.

Award system

Left 4 Dead will include Steam's achievement system, recording players' accomplishments and mishaps. Part of the intent of this system is to help players to avoid griefers and to find teammates with more experience. To help ensure good teamwork among the players, the game provides positive feedback for good behavior (such as aiding fallen comrades) and negative feedback for poor behavior (such as the shooting of one's own team members), but these rewards and punishments do not carry over from round to round. A global, persistent "merit/demerit" system, which would have tracked these good and bad behaviors for each player, was originally planned for inclusion in the game to give all players an incentive to engage in good in-game behavior, but this system was removed late in the development of the game in favor of immediate, non-persistent feedback displayed in-game.

Xbox 360 version

The Xbox 360 version of Left 4 Dead has the same game modes as the PC version. The game supports split screen and system link play. Players can mix split screen and online play in the same game. A new matchmaking system is also included for online play.

Valve will run dedicated servers on Xbox Live for Left 4 Dead.

Survivor characters

File:Left 4 Dead Revised Cast.jpg

The final design of the Survivors. Left to right: Francis, Bill, Zoey, Louis

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The original design of the Survivors. Left to right: Louis, Francis, Zoey, Bill

There are four playable human characters in the game (hence the "4" in the title). Early plans were for players to be randomly assigned to characters, though in the final release players can choose any character they would like so long as another player has not selected it first.

• Francis is a tattoo-covered biker.
• Zoey is a college student and horror movie enthusiast.
• Louis is a Junior Systems Analyst in his company's IT department.
• Bill is a former Green Beret and a Vietnam veteran.

First tier weapons

Survivors are armed with various firearms divided into two tiers. The first tier is available for everyone to select from when the scenario starts in addition to the one or two Springfield Armory M1911 pistols all Survivors always carry. The pistols have unlimited ammo and are the only weapon that Survivors can use when they are knocked down by the Infected. Survivors all have a melee attack, which is very useful as they can use it to push away infected by hitting them. Survivors use this to push infected away and then attack them, or to get time to reload. Also, the player can reload, melee, and continue the reload process throughout the melee attack. The first tier contains the standard Uzi, pump-action shotgun, and a double pistol.

Second tier weapons

Weapons in the second tier can be found throughout the maps and at the end of the scenario, just before the final fight. The second tier, in addition to having a wider variety of weapons, also provides weapons that fulfill the same role as first tier weapons but are inherently better, such as replacing the Uzi submachine gun with the M16A3 assault rifle - and the standard pump-action shotgun with the Benelli M4 Super 90 shotgun. Along with those, players also receive a scoped Ruger Mini-14 rifle.

Additional weapons

In addition to firearms, Survivors can also carry either a Molotov cocktail to create a pool of fire on the ground which lights infected on fire (which damages bosses over time and causes normal Infected to panic and die) or a pipe bomb bedecked with bright strobe lights and a high pitched siren squeal designed to attract the Infected. In addition to these weapons, miniguns can be found mounted in defensible positions in some areas of the game, while gas cans, propane tanks, and oxygen tanks could be placed and set off for a wide-area fire or explosion, similar to the Molotov cocktail/pipe bomb. A player can also lose health by walking into the fire. The player burns for a few seconds, losing health until the fire is extinguished. When an infected is set on fire it does not go out, and the infected continues to lose health until it dies.

Additional items

Each survivor is able to carry a single first-aid kit which will heal 80% of damage taken, meaning a player who is close to death would benefit more from a first-aid kit than one who has taken little damage. First-aid kits are primarily found in the safe rooms at the end of each level. Also scattered about the levels are pain killers which temporarily heal 50% of damage taken. Any survivor can heal or give pain killers to a teammate.

Infected characters

The Infected are the Survivors' foes in Left 4 Dead, and they appear to be partly inspired by the infected from several modern films, including Dawn of the Dead, I Am Legend, and 28 Days Later. The 'Common Infected', as opposed to the slow, shuffling zombies associated with George A. Romero's Dead series and the Resident Evil series, are fast and agile, creating quite a formidable foe. They can be dealt with easily on their own, but in great numbers are difficult to defeat. In addition, there are five mutated Infected who have their own special mutant abilities and are more powerful than the regular Infected. These special Infected make distinctive sounds to announce their presence, sometimes followed with a survivor shouting out, e.g. "Hunter!" Four of the six Infected characters are playable in Versus mode.

• The Horde is a large swarm of rushing Infected who are brawlers more than biters, at once similar to 28 Days Later, using their sheer number to attempt to overcome the Survivors. Hordes can be triggered due to a Survivor being splattered by a Boomer, setting off a car alarm, at seemingly random moments, and staying at an area for too long. Horde events are also more probable if the Survivor team plays efficiently. The Horde is prefaced by a musical horn cue in the soundtrack.
• The Boomer is a distended and bloated Infected that can spew projectile vomit at the Survivors, blinding them temporarily and triggering a swarm of Infected. Boomers blow up when they die, spraying nearby Survivors with bile that also attracts the Infected. Boomers also have the ability to hurl themselves off buildings and detonate on impact with the ground but it is not clear if this is intentional.
• The Hunter is an agile Infected who can climb walls and jump over rooftops, similar to I Am Legend Infected and Half-Life 2's Fast Zombie. Crouching for some time gives the Hunter access to a powerful pounce attack that pins a Survivor down and it then starts to slash at the Survivor. It continues to slash at the pinned Survivor until the Hunter is knocked off or the Survivor is killed. The Hunter can be identified by its distinctive scream and growls.
• The Smoker has a long, grasping tongue which can stretch up to 15 meters (50 feet). It can capture Survivors as it drags them away from their team mates, or dangle them a foot off the ground if pulled from a rooftop, similar to Half-Life's Barnacle and Resident Evil's Licker. When the Smoker is destroyed, it leaves a haze of green smoke that distorts the players' vision in the game and causes the character to start coughing, preventing them from using voice commands. The Smoker can be identified by its coughing and strained breathing, along with the cloud of smoke that comes off of it.
• The Tank, a huge, muscular, and noisy Infected, bears some resemblance to The Hulk or The League of Extraordinary Gentlemen's Mr. Hyde and is capable of throwing large items such as cars or blocks of concrete. Players cannot choose to be the Tank; Infected players are randomly chosen to spawn as one. The Tank can take the most amount of damage before dying and can deal a lot of damage. The tank has a "Frustration Meter" which means that control will be taken away from a human player if the Tank does not engage the survivors for a certain time when playing as the Tank. The Tank's presence is foreshadowed by a musical cue and the area quaking.
• The Witch is the only mutant Infected that cannot be played by human players. Witches can easily be detected by their loud, distinctive crying and by the eerie choir music that swells up as the player draws near. Witches are not aggressive and can be avoided by careful players, but flashlight beams, physical contact, prolonged staring, and loud sounds such as gunfire or car alarms in their vicinity rouse them, causing them to attack whichever player startled them. When a Witch takes sufficient damage or kills the player who startled her, she retreats, covering her face and screaming horrifically. The lethality of a Witch is dependent on the difficulty of the game, and on all difficulty levels, the witch can knock down a player in one attack and swiftly kill them. On the "expert" difficulty, her attack is fatal at first strike. Offensively, Witches are far more dangerous than Tanks, but they are generally easier for players to kill. Compared to most Infected, they can withstand a large amount of damage before dying, but much less damage than a Tank. Due to the extreme danger Witches pose to players at all difficulty levels, there is very little benefit inherent in fighting them, except to obtain the handful of Witch-related Achievements (earned by, e.g., killing a Witch with a single headshot). When a Witch does not directly block the players' path, it is generally better to sneak past her rather than to risk a Survivor's life by engaging her in needless combat.

Development

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Before and after the application of cinematic effects

Development on Left 4 Dead started in mid-2005. Valve aimed to create a horror film-inspired game that merges single player games' character-driven narrative structure with multiplayer games' social interaction and high replayability. The game was first revealed in the Christmas 2006 publication of PC Gamer UK with a six-page article describing a playthrough at Valve's headquarters. A teaser was released with The Orange Box. The game was first playable at the Showdown 2007 LAN in San Jose and at QuakeCon 2007. Turtle Rock Studios announced Left 4 Dead on November 20, 2006, and was acquired by Valve Corporation on January 10, 2008 because of the game and long-standing relationship between the companies. Certain Affinity announced in February 2008 that they are assisting with the Xbox 360 version of the game. The game opened up to pre-purchasing on Valve's Steam system on October 15, 2008.

Left 4 Dead uses the latest version of Valve's Source engine, with improvements such as multi-core processor support and physics-based animation to more realistically portray hair and clothing, and to improve physics interaction with enemies when shot or shoved in different body parts. Animation was also improved to allow characters to lean realistically when moving in curved paths. Rendering and artificial intelligence were scaled up to allow for greater number of enemies who can navigate the world in better ways, such as climbing, jumping or breaking obstacles. Lighting has been enhanced with new self-shadowing normal mapping and advanced shadow rendering that is important to convey information about the environment and player actions. Wet surfaces and fog are used to create mood.

Many kinds of post processing cinematic visual effects inspired by horror movies have been added to the game. There is dynamic colour correction that accentuates details based on importance, contrast and sharpening to focus attention on critical areas, film grain to expose details or imply details in dark areas, and vignetting to evoke tension and a horror-film look.

Demo

Early access to the Left 4 Dead demo for people who pre-ordered the game began Thursday, November 6, 2008 on both Windows and Xbox 360. It gave users access to both online and single player play in 2 levels of one story within the game. This promotion is being offered in addition to the 10% savings for those who pre-order and applies to all Steam Windows pre-orders and all Windows and Xbox 360 pre-orders from GameStop and EB Games in North America. However, many of the people who pre-ordered the game through GameStop did not receive their demo codes on time to play the demo on release. This may have been due to a glitch in GameStop's website, which allowed anyone who signed up to receive the demo key, whether they had pre-ordered or not.

On November 11, the Left 4 Dead demo was made available to all Windows and Xbox 360 gamers worldwide. The demo concluded on November 18, when Left 4 Dead was made available at retail outlets across North America and worldwide via Steam, in order to use the dedicated servers for the full game.

Demo private server issues

The demo had many server problems and game glitches, primarily Valve's strategy for server management which made it impossible to set up a dedicated private server with administrator controls. However, a stream of patches led to the availability of a server browser and basic private server functionality as well as Valve's acknowledgment of player concerns. It appears that a patch released just before the game itself has resolved many of the connection issues that demo players were having.

Reception

Reception

Left 4 Dead received almost unanimous praise from critics, averaging a 91% on Game Rankings and 89% Universal Acclaim on Metacritic, in particular for its procedurally generated movie-like experience. G4 said that the game captured the horror movie feel perfectly and that multiplayer was extremely addictive. IGN stated that "It's almost pitch perfect in how it captures the tension and the action of a Hollywood zombie movie" and went on to describe it as "quite possibly the perfect co-op shooter". IGN noted that the Source engine was no longer cutting edge, but was favourable towards the visuals, describing the lighting as "amazing" and praising the emotive facial animation and detailed, cluttered levels.

Common points of criticism were the limited content and lack of overall narrative. While giving the game a "lasting appeal" score of 9, IGN noted that the small number of scenarios may feel "limited", while GameSpy found the lack of background narrative "disappointing" (although noting that there's "reportedly a lot of DLC planned [..] that will expand upon the story").

On October 28, 2008, Valve reported that preorders for Left 4 Dead had beaten those of The Orange Box by 95% after the Steam pre-order was launched.. On November 21, 2008, the day of the games release in Europe Valve issued a press release stating in total Left 4 Dead had exceeded the pre-order numbers of the Orange Box by 160%.

See also

• List of undead-themed video games